I have a 78 f-150 400 C6 and i have trouble starting it, in hot or cold. In hot weather it may start after i pump it a few times on the first try, i let it warm up for a while and she'll run pretty good. But when the weather is cool or cold i have to pump it and start it about 3 or 4 times to keep it running. It will usually start up on the first time when it has been runnin/the motor is warm. The carb is rebuilt i was just wondering what would be making it do that. The motor is completely stock so im just wondering if something is clogged or whatnot. Thanks, 78jpa

 

have you checked to see if the choke is closing properly, if when the carb was rebuilt the linkage wasn't put on right or was bent it wouldn't work. it really sounds like a choke problem though atleast to me.

 

My first inclination would be the choke needs to be looked at. Another thought that will contribute to the problem, especially in cold weather, is if you are running with an open filter aftermarket breather, you won't be utilizing or benifitting from any of the hot air choke assist components that are part of the original choke system.